


H(ollow)een Party

by piinkmocha



Category: Undertale (Video Game)
Genre: Bathroom Sex, F/M, Female Frisk, Halloween Costumes, Kinda, Plot What Plot/Porn Without Plot, Public Sex, i know its not even October yet I just wanted to write, the title is supposed to be a pun
Language: English
Status: Completed
Published: 2017-09-20
Updated: 2017-09-20
Packaged: 2019-01-01 02:47:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,576
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12146970
Author URL: https://archiveofourown.org/users/piinkmocha/pseuds/piinkmocha
Summary: Sans thinks Frisk looks fantastic in her Halloween costume.





	H(ollow)een Party

**Author's Note:**

> Get it? Because skeletons are hollow?  
> I'm going to hell. Happy (early) Halloween, you dirty fucks. 
> 
> (ALSO - this is an AU. Where Frisk just kind of stayed Underground with the monsters. Roll with it.)

Bright orange lights, a fog machine, pumpkins, gummy brains served on large platters, monsters in costumes dancing to some remix of "Spooky Scary Skeletons" (Papyrus obviously chose the music) - everything around Frisk  _screamed_ Halloween, and she  _loved_ it. 

 

She had been rather surprised to find out monsters celebrated Halloween, especially since the holiday  _above_ ground could've been considered a mockery to their existence - the humans having driven them down here in the first place and all - but it was a pleasant surprise, since Halloween was Frisk's favorite Holiday. She loved Fall in general, as she adored the colors of the leaves on the trees, the crisp feeling in the air, the clear night sky - 

Well, at least, back when she  _could_ see those things, she had really enjoyed them. She'd lived down here, with the monsters, for a couple years now, and, as much as she loved the friends she had made, she very much missed seeing the beautiful colors that nature had to offer on the surface when Autumn came around. 

 

Currently, she stood in Sans and Papyrus's house, along with... pretty much every other monster in Snowdin. Alphys and Undyne were here, too, as well as Mettaton and Napstablook. She had always felt rather out of place at parties, even Halloween ones. She couldn't keep up with the others, and often times just hovered near the punch bowl, scanning the crowd for people she knew. It was no different tonight - she watched her friends dance, talk, and drink, but didn't join in herself. 

 

She was dressed up as a witch - wearing a small black dress that flayed out just below her thighs, accompanied by knee high black stockings and a small, pointy witch hat. On her feet, she wore short, black heels. Her arms were adorned with black, laced sleeves that left holes for her fingers, and her hair was parted to cover her exposed shoulders, though her cleavage was extremely visible, which was obviously intentional. She had dark makeup on, making her look much older than she actually was - she sported orange and black eye shadow, black lipstick, light eyeliner and just a bit of glitter. Truthfully, she believed she looked great - and she wasn't the only one.

 

"Kid?"

 

A voice startled her out of her thoughts, and she turned to see Sans - the Skeleton wore small black bat wings and a mask over his mouth. The mask was a little creepy, admittedly - it displayed a wide, toothy smile. It would have unnerved Frisk, had she not been so used to seeing creepy beings walking around. She waved at him as he approached, offering a smile.

 

"You look fantastic," Sans stated when he approached, quickly eyeing her up and down and winking at her. Frisk blushed and laughed, covering her mouth. 

"Well thank you. I try."

"You don't have to try to look good. You just do. Always." 

 

Frisk watched as he poured himself a glass of punch. The skeleton lowered his mask slightly to take a drink, and then set the cup down. 

 

"You look lonely over here. The party is out there." He gestured towards the main floor, where a remix of 'This is Halloween' now played - jeez, Papyrus had picked the most basic music ever, hadn't he? Orange and white strobe lights flashed, lighting up the fog that clouded the room. It was creepier to think that these were literal  _monsters._ For someone who had never seen them before, it would be a terrifying sight. 

 

"I know," she replied, biting her lower lip thoughtfully. Sans was obviously waiting for her to say something else, but she had nothing else to say - it wasn't as if she didn't enjoy parties, she just always felt so out of place at them - even more so now, being surrounded by creatures of a different species. Quite literally. 

 

"Not a fan of flashing lights and loud music?" Sans joked. "I know a place we can go to ditch it for a little while. If you want."

Frisk threw a glance at him, her heart pounding when she realized what he was offering. It was a bold move on his behalf - she knew if she said no, he would be just fine with it, and things would continue as if it had never happened. Sans was cool like that.

But she had always had a small crush on Sans - as weird as it was, she realized there was something about this skeleton she found very attractive. 

 

She didn't bother thinking too much about that. It was weird. 

 

"A place?" Interested, she turned to face him - Sans was about as tall as her, which was strange, considering how most monsters towered over her. Sans nodded, pushing his smiling mask back up. She bit her cheek thoughtfully and nodded, hoping her blush wasn't visible in the dark room. "Yeah. okay. But what kind of place?"

 

"A top secret one," Sans replied, grabbing her by the hand and guiding her through the crowd of monsters. She briefly hope nobody suspected anything - wouldn't it be bad if it got out that she was going somewhere alone with Sans? In the middle of a Halloween party? Then, she noticed that nobody was really looking at her. They were all busy dancing or talking, just having a good time. She exhaled with relief as they pulled out of the crowd and Sans led her up the stairs, and for a moment, she thought he was taking her to his bedroom. The thought was a bit exciting, because nobody  _ever_ went into Sans' room, except Papyrus. 

 

Then, he veered sharply to the left, gently pulling her into the bathroom and closing the door behind them. When he flipped on the light switch, he looked over her again, stating, "your costume looks even better in the light, you know that?" 

Frisk couldn't help but blush.

 

Everything that happened next happened rather quickly for Frisk - sans had her pressed against the wall next to the sink, his smiling mask pulled down so it dangled around his neck so he could kiss her, his tongue gliding between her lips easily. He skimmed his hands down her waist, feeling the skin tight costume with a satisfied hum before pulling her closer, digging his bony fingers into her hips. 

 

Frisk was momentarily concerned that someone would hear them - there were monsters on this floor as well, though not nearly as many as there were downstairs. The door wasn't locked, and she couldn't think of anything more embarrassing than being walked in on. 

Sans must have noticed she was distracted, because he pulled away, a mildly annoyed look on his face. 

Frisk giggled and apologized, stating, "why don't you lock the door?"

 

The look of annoyance faded, replaced with amusement and a hint of smugness. "Oh? You scared someone is gonna walk in on you getting fucked by a skeleton?" Frisk knew it was a joke, but it was a crude one, and it flustered her. She nodded, and Sans chuckled. 

For a moment, she actually thought he was going to make her feel better and just  _lock the damn door,_ but it couldn't be that easy, could it?

 

He abruptly became very rough, spinning her around and pinning her arms to her back by her wrists. Her hat fell to the ground beside them. He brushed his thumbs over the lacy sleeves she wore, whispering, "I hope everyone hears this, Frisk." 

She didn't have it in her to argue - her face was dark red, as she wasn't used to Sans calling her anything besides 'kid.' It was... well, it was hot, if she was being honest with herself. 

 

She felt Sans sliding her underwear down with one hand from under her short dress, and saw them tossed across the bathroom, landing gracefully over the shower head. Using the same hand, he lifted up her dress, completely exposing her thighs and everything in between. He exhaled softly, pulling his mask from around his neck and setting it on the toilet lid beside them before turning his attention back to his partner.

Then he was on her - or,  _in_ her. She couldn't see him, but she felt his tongue against her clit and she let out a shaky breath, her eyes sliding closed. Sans didn't stop there - he was just getting started, gliding his tongue into her pussy and prodding it around inside of her, eliciting a moan from Frisk as she felt her knees begin to shake. Sans obviously liked that - he removed his tongue in favor of a couple of fingers, striking upwards into her g-spot to milk more noises out of her - and he did a good job, obviously, because she moaned a bit louder, wiggling her hips on his fingers. 

The hand that he'd been using to pin her wrists suddenly moved, and he was grabbing both of her ass cheeks, spreading them wide apart before plunging practically his entire face into her backside, tonguing her vagina viciously. Frisk whined, her knees suddenly collapsing, and she slumped to the floor, forcing Sans to briefly move back away from her.

 

"Don't make this harder than it needs to be, princess," he murmured into her ear, sending shivers down her spine. Suddenly, she was tugged to her feet, and before she could say anything, she was bent over the sink, her head almost touching the mirror in front of her.

_The mirror._

"You're going to watch me fuck you," Sans purred, pulling out his dick - which she assumed was formed from his magic, because generally speaking, skeletons lacked genitals - and, God, he'd given himself a fairly big one. It almost scared her, but she was so turned on that she almost didn't care if he ripped apart her insides.

 

"Do you want it?"

Sans brushed his dick against her thighs, sliding it over her pussy but not quite putting it in, causing her to groan and wiggle her hips again.

"Yeah," she breathed after a moment. She felt utterly helpless, bent over a bathroom sink in a skimpy Halloween costume, at the mercy of a magical monster. "I- yes. Please, I do."

 

She half expected Sans to make her call him daddy or some shit, but in the next moment, his cock was inside of her, filling her up in the most wonderful way.

She wasn't totally inexperienced - she had had sex before, one time. She had pretty much suppressed that memory now, but in this moment, she couldn't help but remember it as a comparison. Sans hadn't even moved yet, and it already felt so much better than last time.

 

"Am I your first?" Sans practically read her mind.

She was slightly embarrassed by the question, and she stammered, "I- um... no."

 

She expected him to be disappointed. She really did. However, Sans leaned over her, effectively fitting his entire length into her, causing her to gasp and whine loudly. His breath was warm on her ear.

"Good. Because I'm going to fucking destroy you."

 

She wasn't given time to react. He began to slowly thrust himself in and out of her, earning a few loud groans for his effort. Frisk's fingers gripped the sink as best they could as he picked up the pace, hitting her  _just right_ and  _fuck, this was so much better than her actual first time-_

"Ah-- Sans, fuck, please. Fuck!" She was being shamelessly loud, fucking him back, moving her hips in rhythm with his thrusts as if it was the only thing that mattered anymore. Her head spun with a mixture of pleasure and dull pain as his cock slammed into her relentlessly. She heard Sans groaning and panting behind her, the occasional moan slipping past his lips. He was cursing under his breath, too, she was sure of it - but she couldn't make out the exact words.

 

It didn't really matter.

 

Glitter from her costume floated to the ground around them from the sheer force of the sex.

 

 "Sans, harder - fuck, please-" 

"Kid," he panted quietly, wrapping one hand around her throat and pulling her head back, "shut the fuck up before I _make_ you." 

She wanted to be offended that he'd told her to shut up - especially in the middle of fucking her - but part of her  _really_ liked Sans taking control, and she wanted  _more_ of it. Between pants, she tried to retort. "Why don't... you... fucking make me, th-"

 

She didn't get to finish her sentence. Sans dug his fingers into her throat - carefully, she could tell, so as not to hurt her _too_ much - and used the other hand to grip her waist and he fucked her  _harder._ She was losing her damn mind - she  _screamed,_ her entire body shaking from the force of his cock. Sans hissed something like  _'quiet down'_ but his words fell on deaf ears. She had never been this fucking  _wet_ before - it was  _fantastic._

 

There was suddenly a knock on the bathroom door, and  _son of a bitch it's not fucking locked-_

"Is everything okay in there?" The robotic yet flamboyant voice of Mettaton sounded through the door, and Frisk gritted her teeth, her heart racing in a mixture of panic and just overwhelming pleasure. She was about to finish, there was no way this could be happening. 

 

Sans moved his hand from her throat to her hair, tugging it roughly and whispering, "answer him, Frisk. That was a girly scream." He definitely did not slow down his aggressive pace. He was doing this on  _purpose-_

"Are- are y-you serious?" She whispered back, frantically swallowing when he didn't answer. Trying to ignore the dick inside of her, she managed to call out, "I- I'm fine! Be o-out in a- a second!" 

 

There was no response, so she assumed he had walked away. Thank  _god_ he hadn't opened the door. 

"Frisk," Sans breathed heavily, "I'm gonna cum."

 

Frisk briefly considered asking him to pull out, but she remembered Alphys mentioning once that monster jizz didn't get humans pregnant in a passing conversation with Undyne. She kind of wished she'd brought a condom, anyway, but there wasn't time to regret not bringing one right now. 

 

Sans suddenly groaned loudly, and she felt a warm liquid inside of her, dripping from her vagina and down her thighs, effectively getting her knee-highs wet. Sans was determined not to stop until she finished, so he used a couple fingers to stroke her clit while he was still pumping into her, though notably a bit weaker than he had been before.

 

It didn't take much more for her to get there, and she whimpered loudly when she came, knowing her juices would be all over San's fingers. She exhaled a heavy breath as he finally pulled out, his dick shiny with multiple fluids. When she turned to look at him, he stuck a cum covered finger into his mouth and sucked it off right in front of her, earning an unimpressed look from Frisk.

 

"No? Don't think that's hot? Damn, kid." He stepped away from her, allowing Frisk to stand up. She was barely able to stand, her legs shaky and dripping with Sans' cum. She laughed quietly and blushed, suddenly embarrassed, for whatever reason. 

 

Sans grabbed his mask from where it sat on the toilet seat, strapping it back around his face. He pulled his shorts back on and even used a comb to brush his skull.  _What a dick._

 

"Happy Halloween, skeleton fucker."

 

**Author's Note:**

> You can see I got kinda lazy @ the end because I just used "fluids" lmfao pls have mercy
> 
> Don't have unprotected sex kids


End file.
